Automatic air painting unit with transverse oscillating action



Sept. 16, 19 2 J. A. PAASCHE AUTOMATIC AIR PAINTING UNIT WITH TRANSVERSE OSCILLATING ACTION 6 Sheets-Sheet 1 Filed July 30, 1948 INVENTOR.

Sept. 16, 1952 J. A. PAASCHE AUTOMATIC AIR PAINTING UNIT WITH TRANSVERSE OSCILLATING ACTION Filed July 30, 1948 '6 Sheets-Sheet 2 *3 R w w w) INVENTOR. Jms ZJ wce PAASCHE AUTOMATIC AIR PAINTING UNIT WITH Sept. 16, 1952 J, A,

TRANSVERSE OSCILLATING ACTION 6 Sheets-Sheet 5 Filed July 30, 1948 p 1952 J A. PAASCHE 2,610,605

AUTOMATIC AIR PAINTING UNIT WITH TRANSVERSE OSCILLATING ACTION Filed July 50, 1948 6 Sheets-Sheet 4 5 $121 3 m N b INVENTOR.

J aasa/ze Se t. 16, 1952 PAASCHE 2,610,605

AUTOMATIC AIR PAINTING UNIT WITH TRANSVERSE OSCILLATING ACTION Filed July 30, 1948 6 Sheets-Sheet 5 J96 x J95 JNVENTOR.

Sept. 16, 1952 J. A. PAA SCHE AUTOMATIC AIR PAINTING UNIT WITH TRANSVERSE OSCILLATING ACTION Filed July so, 1948 -6 Sheets-Sheet 6 Ji w IN VEN TOR.

Patented Sept. 16, 1952 OFFICE \AUTOMATIC AIR PAINTING UNIT WITH TRANSVERSE OSCILLATIN G ACTION Jens ArBaasche, Chicago, Ill.

Application July 30, 1948, SerialNo. 4158i .14 Claims. 1

This invention is directed generally "to continuousraircoating devices for coating a surface with paint 'or other material, and more specificallyto anoscillatingmechanism to be usedwith aircoating equipment. V

In 'certaintypesof continuous ail-coating processes, oscillating TdVlC8$ are used in combination withendlesswork'conveyors. 'Certainof the oscillating. devices now employed 'use 'a plurality of complex partsmany of them costly, to accomplish the desired results. These devices do not lend themselves readily to repair, Furthermore, many of these -devices do'not ensure'an even aircoating stroke whichis so essential in this type of work. In addition, many of these devices waste paint or other coating material by spraying during part of'tl're time that the workpiece is not under the spray gunsor nozzles.

Therefore, one object of this invention is to provide .a simple oscillating device wherein a minimum number of well-known parts is used in ainove'l manner to obtain'a'n oscillating motion,-

"the simplicity reducing cost ofmanufactur and faciiitatingmaintenance of the device.

Itis another object ofzthis invention to provide a portable and adjustable oscillating 'mechanism which may be usedwith a plurality of machines where suchmotion is desired.

It "is a further object or the'present invention to provide an oscillating device which operates with equal facility in a horizontal or vertical position.

It is still another object of the-present invention to provide :an "oscillating :mechanism which has an evenstroiseinboth directions duringthe oscillating'operation'and wherein the speed of oscillation is readily-controlled.

It is still a further object of the; present invention toprovide an oscillating mechanism which is adapted tobeused withvarious sized units, the unit having means for *adjustably locking "the oscillating mechanism in the desired position relative tothe'unit. v

It is an object of the improved form of this invention to provide an oscillating mechanism with-an improved valve control which is adapted to use a minimum amount of paint or other coating material by causing the airbrushes to cut out and cut in zit-exactly the same position regardless o'f the speed of oscillation. 1

These and manyother important objects of the invention will be more clearly understood upon reading the following detailed description and reference to the accompanying drawings wherein:

Figure 1 is'avsi'de View of a continuous aircoat- 2 ing device showingthe oscillatoryunit in com bination' with-a conveyor platform and hood;

Figure 2 is a'sectional view of theoscillatory unit and conveyor taken along the line2-2 in Figure 1;

Figure 3 is a topview of the oscillatory unit taken along the line 3-3'in' Figure 2;

Figure 4 is a sectional view through the carriage and support taken along the line l4 in Figures; Figure 5 is a front view of the speed control mechanism for the unit taken along the line 5-5 in Figure 3;

j Figure 6 is an end viewrof the'motor for driving the oscillating unit and the mounting therefor taken along the line 6-6 in Figure 3;

Figure '7 is a front view of the carriage previously disclosed in Figure 2;

Figure '8 is a cross sectional view of the carriage taken along the line 8-8in Figure 7;

Figure 9 is a 'front view of a carriage similar to Figure 7 of an improved form of "the invention including also part of the transverse supporting structure;

Figure 10 is a side view, part in section, or" the carriage and support'of the improvedfform of the invention taken along th line Ill-Allin Figure 9;

Figure 11 is a top view of'the carriage and gun structure of the improved'form of the invention taken along the line I I lin Figure 9;

Figure 12 is a sequence drawing of the operation of the valve control cams and followers'in the improved form of the invention;

Figure 13 is a side view, part in section, .of

r one of the cams controlling the valve in the improved form of the invention; v

Figure '14 is a sectional view of the cam disclosed in Figure 13 taken along the line M--M in Figure 13; and

Figure 15 is a sectional view of the valvein the improved form of the invention.

Referring now to the drawings more in detail wherein like reference numerals are used to indicate similar parts throughout the various figures, it will be seen that the oscillatory unit contemplated by the instant invention is "designated generally by the numeral l0. This oscillatory unit I6 is shown in combination with other elements whichtogether comprise an automatic aircoating device. These elements include a corn veyor platform I 2 having'legs l ladapted tosupport side members I 6. Sprocket wheelsllB and 29 are mounted at opposite ends of side members IS on axles 22 and 24,, respectively, and mounted in bushings, (not shown), supported by said side members. Depending arms 26 and 28 are fixed to side members I6 in any convenient manner and adapted to serve as mounting means for axles 30 and 32 on which sprocket wheels 34 and 38 are mounted, respectively, in a fashion similar to sprocket wheels I8 and 20. An endless chain 38 is mounted about the periphery of these sprocket wheels I8, 20, 34 and 36. Another set of sprocket wheels, (not shown), with a chain 4|, best seen in Figure 2, is mounted on the other ends of shafts 22, 24, 30 and 32 in a fashion similar to wheels I8, 20, 34 and 36. Rods 43 are mounted between chains 38 and 4| to provide a platform on which work 39 may be carried into the aircoating hood 40. These chains 38 and 4| may be driven at the required speed by a sprocket wheel on one of the axles connected to a drive means.

Hood 49 is provided to overlie the conveyor platform. Details of the hood will best be understood by a reference to my co-pending application Serial No. 545,812. The hood is comprised of a bodyportion 42 with openings, (not shown), provided over the conveyor platform I2 to permit entrance of the work 39 therein. Window 44 is provided in one wall of the body portion to permit the operator of the device to view the work and is preferably designed in a manner so as-to permit access to the interior of the hood by the operator.

Oscillating unit I is comprised of a pair of standards 46 and 41 adapted to rest on the floor on their bases 48. Upright body portions 49 and of standards 46 and 41, respectively, are adapted to telescopically receive arms 50 and 52. Clamp members 53 and 55 are provided adjacent the ends of body portions 49 and 5I for positioning arms 50 and 52 at any desired height. Joining the ends of the two arms 50 and 52 is a support member or track 54 preferably of tubular construction. Spaced at a predetermined distance below support member 54 is a second support member 56 attached at its opposite ends by means of clamp members 58 and 60. Clamp members 58 and 60 also support a shelf 62, best seen in Figure 3, on which is mounted the driving mechanism, later to be described.

A carriage 63, best seen in Figures 2, 4, 7 and 8, is comprised of two side plates 64 and 66. These side plates are properly spaced relative to each other at their uppermost ends by means of axles 68 and I0 which pass through both plates, shoulders being provided on the axles near their ends to engage the inner surface of the side plates 64 and 66. Threads provided adjacent the ends of the axles accommodate nuts for clampingly engaging the plates 64 and 66 therebetween. Wheels 12 and I4 are rotatably mounted on arms 68 and I0, respectively, and adapted to lie on track member 54. Adjacent the bottom of the side plates 64 and 66 a U-shaped member I6 is secured to the side plates to hold them in predetermined spaced relation to each other. Adjacent the bottom of the side plates, and on either side of the U-shaped member I6, are mounted housings I8, 82, 83 and 85 which are secured in any convenient manner. Vertically arranged axles 84 and 86 have their opposite ends journalled in the walls ofthe housings. Wheels 86 and 90 are rotatably mounted on axles 84 and 86, respectively, the wheels in housings 83 and 85 not being shown in the drawings. A third set of wheels 92 and 94 are mounted adjacent the upper end of side plate 64 immediately below wheels I2 and I4, heretofore described. These wheels are mounted in housings 96 and 98 on 4 axles I00 and I02, respectively. Wheels 12 and I4 carry the weight of carriage 63 and wheels 88, 90, 92 and 94 prevent horizontal shifting of the carriage.

Mounted on the exterior of side plates 64 are two vertically arranged strips of material I04 and I06. These strips of material I04 and I06 may be attached to the side plate in any convenient manner, such as welding, bolts or the like. Strips I04 and I06 form a channel or track which is adapted to coact with the drive mechanism later to be described.

The carriage 63 is adapted to carry a plurality of brackets for mounting equipment to be reciprocated. Figures 7 and 8 show an arm H2 attached at its one end to the U-shaped bracket I6 and adapted to telescopically receive another arm I I4 at its other end to provide an adjustable and extensible mounting for airbrushes or spray guns II6 to be clamped thereon. A C-shaped clamp II'I adjacent the end of arm II2 permits retention of arm H4 in any desired position. Also mounted on the carriage is bracket II8 to which is secured a valve I20 for controlling the supply of air to the airbrushes H6. The valve I20 comprises inlet means I22, outlet means I24 and a valve needle I26. Spring arm I29 is pivotally mounted adjacent the valve needle I26 in its extended position by means of a screw or the like I30. At the other end of spring arm I28 are flanges I32 with a roller wheel I34 mounted therein. Conduits I36 from paint container I38 may also be mounted on the side plates of the carriage as shown in Figure 8. For purposes of disclosure these conduits are mounted in a pair of collars I40 and I42 adapted to be mounted on opposite sides of side plate 66 and to retain the coupling I44 in rigid position relative to the carriage 63.

For operating the valve I20 during oscillation of carriage 63, a pair of stops I31 and I39 are provided. These stops are comprised of C- clamps MI and I43 adapted to be secured to arms 52 and 50, respectively. Integral with the clamps are clamp members I and M! which are adapted to receive arms I49 and I5I telescopically therein. Adjacent the ends of arms I49 and I5I are cam surfaces I53 and I55, respectively, which are adapted to engage the roller wheel I34 of arm I28, whereby valve I20 is closed during the period of engagement with the arms I49 and I5I. Thus, by this simple mechanism, the spraying period of the airbrushes or other means controlled by valve I20 may be controlled.

The driving mechanism for oscillating the carriage 63 comprises a pair of right-angle brackets I46 and I48 mounted on shelf 62, previously described, by means of shoulders I50. Sprocket wheels I52 and I54 are rotatably mounted on the upright flange of brackets I46 and I48, respectively. -An endless chain I56 is mounted over the periphery of these two sprocket wheels. A stud or arm I5! is mounted on the chain I56 and extends laterally outwardly from the chain. Adjacent its free end a small wheel I59 is rotatably secured. This stud member I5I is adapted to lie in the channel formed by strips I04 and I06 on the carriage and to transmit the reciprocatory movement of the chain to the carriage. The shaft I of sprocket wheel I54 is extended through the upright flange wall of bracket I48 and adapted to be positively engaged by a speed reducer unit I58. A motor I is slidably mounted on a support shown generally at I62 which comprises a plurality of shafts I64 on which the mounting rods 29!! and 2522 '5 base lfidoimotor leasisslidablynmounted, as seen bestin Figured Adjacent the ends :of the shafts is .a-plate 1.6.3 on "which a wheel H is supported. Hate 1.6.8 provided with an; aperture I12 throu h which the threaded shaft N4 of wheel v1 passes. The walls of aperture 112 in plate 1.68 notes :a bearing for the end portion I116 of thethreadedshaft I214. The threaded portion of shaft I74. isreceived in a complementary threaded aperture. lie of the base we and serves to lower :andraise motor .166 relative .to the shelf 62. motor shaft .180 is -mounted .a pulley Wheel 1.812 having .a V --shaped periphery. A v shaped belt 1841s adapted to'be "positioned in the yfifihfi'pfid periphery of wheel [82 and over wheel .186, operatively connected tothe speed :re ducer 58. The position of belt 1'84 in the V shaped periphery of wheel 1.52 maybe altered by raising or lowering the position of the motor 161 relative to the shelf 6.2, thus varying the I speed of speed reducer '1 523.

The operation of the oscillating mechanism HJ may be described substantially as follows: Upon actuation of motor I56 the speed reducer I55 is driven at a desired speed which in turn drives chain I59. .Chain 56 with its stud or arm l5! and rotatable wheel I59 engages the walls of the channel formed by strips lot and 6 01. the carriage, thereby driving the carriage 63 in the direction of the chain. As the direction of stud .15.! ,isreversed, after traversing the periphery .Of sprocket-wheel I52 or I55, the stud shifts vertically in the channel formed by strips i164 and 19-5 and reverses the direction of moi/c merit of the carriage 65, Obviously, the distance the carriage 63 moves along tracks 55 and 55 is alway the same, but the lengthof the spraying stroke is readily controlled by the adjust able cam arms M9 and .I5l, heretofore described.

In the improved form depicted in Figure 9, the vertical support member 50a is topped by hemispherical cap I90 whichrnay be formed integral with support 56a or attached in any desirable fashion. Formed integral with support 50a are bosses I92 and I84 in which horizontal support members 5411 and 55a are held by hexagonal nuts L95, L91, L98 and I199 threaded onto threads cut in the ends of supports 54d and 55a. filler tical support members 58c and diet, (the latter not shown), carry adjustable cam mounting rod supports 20! and 293, inc-t shown), held on by C clamps 264, (not shown), and 2135. Cam i'it telescopically Within supports 29! and 2&3 and are held. by clamps 2B5, tnotshown), and 201. Half of each .C clamp may be formed inte ral with its associated cam mounting rod support or may be attached thereto by any suitable means. Clamp 205 is h ld together and can be adjusted ver tically by means of bolts 2.03 whichmay be se cured by nuts or .may be threaded into the c clamp. Clamp '2 G4. is secured to support member 52a in a like manner and is not shown. On the cam mountin rods sea and ice are mounted cams 2.10,, 212, 21M and 2H5, the action of which will be described subsequently. Each cam is individually adjustable horizontallyand is held in place by a set eerewsuch as 2E8 seen in Figures 13 and .14.

Carriage 53a is like carriage 5.3 previously described except as noted. It is comprised of two castings Ma and 66a fastened together at their top ends by axles fidaand "ltd as in the earlier disclosure of carriage .63. The plate 22.8 is mounted on the side of carriage 53s by stud "bolts .222 which are threaded :into casting fifia.

The valve [20a for controlling the supplyof air :to the "ail-brushes llfia-is mounted .on plate 225 contact the cams 210,212, 2H and 258, in a mannor/to be described later.

An air line "226 is connected at one end to outlet means [24a and .to aconduit 228 which passes through the bottom of carriage 63a and on which are threaded nuts 23B and 23.2 which serve to hold the two pieces of carriage 63a together at the bottom. This pipe then leads to the airguns. Aconduit 23 carrying paint may also be held on carriage 63d by any desirable means, (not shown), and also leads to the air=- uns.

Valve 1211a is open only when cam followin member 1224 i-sin an essentially :vertical'position to cause its-roller Ifilla to push up on arm lieu which in turn holdsup valve stem iiiiaand head 12'. When cam follower 2 24 pivots about its mounting stud .225, spring 129 pressing against nut vl3l forces stem lrZfiaand head l2! down to shut ed the valve until arm 128a is again raised to force the valve open. As all the cams are constructed similarly, only the construction of cam 21:4 .is described. Cam 21s consists or non rotating portion 215 slidably mounted on cam mounting rod 200 and held in place by set screw 218. Side plates Zita and 2M1) are held together by and pivot about bolt 2!? on which is threaded nut 21.9. side plates Zita and 28th carry roller .22! on rivet 2.23 which also serves to hold the side plates together. Side plates 214a and 2|;4b are rotatable .90" to the left about bolt 2]! but are normally held in an upright position by spring lit.

7 Figure 1.2 shows a sequence action depicting the cam mechanism operation. in position .A the carriage is first moving to the right with the valve open. As finger 2241) strikes the roller 22] of cam 2M. cam follower .224 is pivoted to the position shown atB and valve 520a closes. As finger 224a strikes the roller of cam 2l6, it causes the pivotable part of cam Zlfi to pivot to theright as shown in dotted lines at D without altering'the position of cam follower 22 3. The

action of the spring causes thepivoted portion of cam 2E6 to return immediately to its normal vertical position. After carriage 53a reaches its furthermost position to the right and starts back, finger 224a encounters therollcr of cam 2H6. As the pivotable portion of. cam 2!.6 will not pivot to heleft, cam follower 224 is returned to a Ver tical position as shown at .0 thus opening the valve 1213a. When finger 2261b encounters the roller 22! of cam 21-4, .117 causes the pivotable portion of .cam 214 to pivot to the left as shown in. dotted lines at A without altering the position of cam follower 224. The pivoted portion of cam 12M is then returned to its normal vertical position by the action of spring 213 and the carriage continues to the left where its cam follower 224 meets cams 2I2 and 2m with sim ilar results. Evidently the opening and closing of the valve at difierent points will operate to Arm [28a is pivotally mounted adjacent save a considerable quantity of paint or other material.

As a result of this invention an oscillating mechanism may be inexpensively produced, and by reason of its simple construction, readily repaired when the occasion demands.

Furthermore, the oscillating carriage of the unit is driven at a uniform rate of speed, which speed may be controlled as desired. This uniformity of action is essential where spraying apparatus is to be associated therewith in order to insure even distribution of material sprayed on objects passing therebeneath. By reason of the ability to control the speed of oscillation it is possible to use this unit with many different machines having movable platforms which move at various rates of speed.

While in the foregoing paragraphs and ac= companying drawings, two of the preferred em= bodiments of the invention have been disclosed, it is to be understood that these disclosures are for purposes of description only, and that the invention shall be limited only by the scope of the appended claims.

The invention is hereby claimed as follows:

1. An oscillatory mechanism comprising a track mounted on a support, a carriage translatably mounted on said track, a valve member mounted on said carriage, said valve member including a valve stem and a valve head, shoulder means on said carriage for engaging a stud member, individually adjustable means vertically displaced only slightly from the line of movement of said valve stem and valve head and mounted at each end of said tracks for operating said valve member, and means for oscillating said carriage including continuous drive means mounted over the periphery of a plurality of wheels, means to rotate said wheels, and a stud member mounted on said drive means and coacting with said shoulder means on said carriage for imparting an oscillatory movement thereto upon rotation of said wheels.

2. An oscillatory mechanism comprising a track mounted on a support, a carriage translatably mounted on said track, a valve member mounted on said carriage, said valve member including a valve stem and a valve head, means on said carriage for engaging a stud member, individually adjustable cam arms mounted at each end of said track and displaced vertically only slightly from the line of movement of said valve stem and valve head for operating said valve member, and means for oscillating said carriage including continuous drive means mounted over the periphery of a plurality of wheels, a variable speed drive mechanism adapted to rotate said wheels, and a stud member mounted on said continuous drive means imparting an oscillatory movement to said carriage as said continuous drive means is driven over the periphery of said wheels.

3. An oscillatory mechanism comprising a track mounted on a support, a carriage mounted on said track, a valve member mounted on said carriage, a pivotally mounted spring arm mounted on said carriage adjacent said valve member for operating said valve member, means on said carriage for engaging a stud member, adjustable cam arms mounted at each end of said track for engaging said spring arm to operate said valve member, and means for oscillating said carriage including continuous drive means mounted over the periphery of a plurality of wheels, a variable speed drive mechanism for driving said wheels, and a stud member on said drive means adapted 8 to engage said stud engaging means on said car-} riage to oscillate said carriage as the endless belt is driven over the periphery of said wheels.

4. In a continuous aircoating device including an endless conveyor for carrying work to be aircoated, said conveyor being mounted on a support, an oscillatory unit arranged transversely of said conveyor and comprising a translatably mounted carriage on a support, means for causing said carriage to oscillate back and forth, a plurality of airbrushes mounted on said carriage, a valve mounted on said carriage for controlling the operation of said airbrushes, a plurality of cams fixed adjacent each extremity of operation, and adouble acting cam follower mechanism in the form of a spider with a plurality of fingers thereon actuated by said cams, said cam follower mechanism controlling said valve as said carriage is oscillated transversely of said conveyor.

5. In a continuous spraying device including an endless conveyor for carrying work to be sprayed and an oscillatory unit arranged transversely of said conveyor and comprising a translatably mounted carriage on a support, means to oscillate said carriage in timed relationship with said conveyor, and a plurality of spray guns mounted on said carriage, means for controlling the operation of said spray guns comprising a pair of individually adjustable cam arms mounted on the carriage support, a pivotally mounted spring arm carried on said carriage, a valve member mounted on said carriage adjacent said spring arm, said spring arm engaging said adjustable cam arms during oscillation of said carriage and operating said valve for controlling the operation of the plurality of spray guns.

6. An oscillatory unit for mounting spray guns comprising a support, a carriage translatably mounted on said support, means for causing said carriage to oscillate upon said support, a spray gun mounted on said carriage, a valve mounted on said carriage for controlling the operation of said spray guns, a pair of cams fixed adjacent each extremity of the path of travel of said carriage, and a double acting cam follower mechanism mounted on said carriage and actuated by said cams, said cam follower mechanism controlling said valve as said carriage is moved on said support, one of said cams at each end of said path of travel serving to move said cam follower mechanism to the inoperative position and the other of said cams serving to move said cam follower mechanism to the operative position.

7. In a spraying device including an oscillating carriage and a spray gun mounted thereon, a valve mounted on the carriage for controlling the operation of the air gun, a pair of cams mounted adjacent one end of the path of travel of said carriage, and a double acting cam follower mechanism mounted on the carriage and actuated by said cams, said cam follower mechanism controlling said valve as the carriage is oscillated, one of said cams at the end of said path of travel serving to move said cam follower mechanism to the inoperative position and the other of said cams serving to move said cam follower mechanism to the operative position.

8. An oscillatory mechanism comprising a support, a track mounted on said support, a carriage translatably mounted on said track, means for oscillating said carriage upon said track, a spray gun, a valve mounted on said carriage for controlling the operation of said spray gun, a pair of cams fixed adjacent each extremity of the 9 r path of travel of said carriage, and a double acting cam follower mechanism mounted on said carriage and actuated by said cams, one of said cams actuating said cam follower mechanism when the carriage moves in one direction, and the other of said cams actuating said cam follower mechanism when the carriage returns in the other direction.

9. An oscillatory mechanism as' set forth in claim 8 wherein said cam are individually and independently adjustable with respect to each other and the support.

10. In an oscillatory mechanism including a support, a track mounted on the support, a carriage translatably mounted on the track, a spray gun mounted on the carriage, and means for oscillating said carriage upon said track, a spray gun actuating and controlling mechanism comprising a valve for controlling the actuation of the spray gun, a plurality of cams mounted adjacent each end of the path of travel of said valve at the extremities of the path of travel of said carriage, and a double acting cam follower mechanism mounted in a fixed position with respect to said valve and adapted to be actuated by said cams, said cam follower mechanism controlling said valve as the carriage is oscillated.

11. In an oscillatory mechanism including a support, a track mounted on the support, a carriage translatably mounted on the track, a spray gun mounted on the carriage, and means for oscillating said carriage upon said track, a spray gun actuating and controlling mechanism comprisinga valve for controlling the actuation of .the spray gun, a plurality of cams mounted adjacent each end of the path of travel of said valve at the extremities of the path of travel of said carriage, and a double acting cam follower mechanism in the form of a spider with a plurality of fingers thereon actuated by said cams, said cam follower mechanism controlling said valve as thecarriage is oscillated.

12. In a spraying device including an oscillating carriage and a spray gun mounted thereon, a

, valve mounted on the carriage for controlling the operation of the spray gun, a pair of cams mounted adjacent one end of the path of travel of said carriage, a line interconnecting said cams being substantially parallel to the path of travel of said carriage, anda double acting cam follower mechanism mounted on the carriage and actuated by said cams, said cam follower mechanism controlling said valve as the carriage is oscillated, the cam positioned outwardly with respect to the path of travel of said carriage being effective to move said cam follower mechanism to the spray, initiating position, the cam positioned inwardly along the path of travel of said carriage being effective to move said cam follower mechanism to the spray interrupting position.

13. An oscillatory mechanism comprising a support, a track mounted on said support, a carriage translatably mounted on said track, means for oscillating said carriage upon said track, a spray gun, a valve mounted on said carriage for controlling the operation of said spray gun, a

other and the support.

pair of cams fixed adjacent each extremity of the path of travel of said carriage, said cams being arranged in a line substantially parallel to the path of travel of said carriage, and a double acting cam follower mechanism mounted on said carriage and actuated by said cams, the outermost cam ofv each pair of cams being effective to move said cam follower mechanism to the spray initiating position, the innermost cam of each pair of cams being effective to move said cam follower mechanism to the spray interrupting 7 position.

14. An oscillatory mechanism as set forth in claim 13, wherein said cams are individually and independently adjustable with respect to each JENS A. PAASCHE.

REFERENCES CITED The following references are of record in the file of this patent:

' UNITED STATES PATENTS 

